Starting Position: Hold both hands overhead. Keep feet wide apart with the toes pointed out slightly. Contract/brace the abdominals as if receiving a punch to the midsection and hold. Progress: Sit back and squat until the thighs are parallel with the ground. Do not let the knees past the toes. Return to the starting position by pushing through the heels. At the end range, the knees should still be slightly bent, do not lock the knees out. Repeat. Tips: Knee, Shoulder Precautions. The shoulders and hips should rise and fall at the same tempo. Upon returning to the upright position, push through the heels and utilize the legs and not the lower back. Do not let the knees pass the toes throughout the set. Sit back and allow the knees to move backward. Do not allow the knees to move in and out.